Safety elevator mechanism.



J. M. ANDREWS.

SAFETY ELEVATQR MECHANISM.

APPLICATION FILED APR.24, 1913.

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JOHN M. ANDREWS, OF NEW ss'ijiroao, MASSACHUSETTS.

sArE'rY ELEVATOR MECHANISM. 5

I up??? Specification of Letters Patent.

Patented Aug. 26,1913.

Application filed April 24, 1913. Serial No. 763,394.

To all whom it may concern:

Be it known that 1, JOHN M. ANDREWS, a citizen of theUnited States, residing at New Bedford, in the county of Bristol and State of Massachusetts, have invented a new and useful Improvement in Safety Elevator Mechanisms, of which the following is a specification.

My invention hasreference to an improvement in elevators and more particularly to an improvement in safety elevator'mechanism or locking mechanism, adapted to automatically lock or hold the elevator from falling on the breaking of the hoisting cables or The object ofmy invention is to automat-ically lock or hold an elevator from fall ing on the breaking of the elevator hoisting cables.

Another object of my invention is to pro vide the automatic looking or holding mech anism with means for unlocking or releasing, whereby the elevator may be safely lowered down to the next floor and the passengers released from the elevator.

A further object of my invention is to provide means for holding the elevator at each floor when required. 7 a I A final object of my invention is to simplify the construction of automatic safety mechanism for elevators, thereby reducing the cost of manufacturing and installation.

My invention consists in the peculian'an'd novel construction of an automatic safety elevator mechanism, said mechanism having details of construction, as will be more fully set forth hereinafter and claimed. a

Figure 1. is a vertical sectional view through an elevator well showing an elevator provided with my improved safety mechanism, the elevator in full lines in a normal running position and in broken lines in a locked position on the breaking of the hoisting cables. Fig. 2. is'an enlarged vertical sectional view through the elevator showing a portion of the elevator broken away and the safety mechanism in its normal inoperative position. Fig. 3. is an enlarged detail vertical sectional view through one of the locking rope drums and locking slides show ing the drum locked by theslide. Fig. 1. is

an enlarged detail sectional view of the lock-' ing drum'and part of the slide, looking down on the same in the locked position, and Fig; 5. is an enlarged detail vertical view partly in section of'the unlocking or releasing device.

In the drawing 7 indicates an elevator well, 8 a passenger elevator and 9 the elevator hoisting cables. The elevator 8 is provided with two rods 10.-10. rigidlysecured to the top of the elevator in a vertical position. 7 A horizontal bar 11 is slidably secured to the rods 10. 10. and is held in its normal upward position on the rods 10. by an'enlarged head 12 on the upper end of each rod 10. and'the pull ofthe hoisting cable 9. The hoisting cable 9 is secured to the bar 11. by a pulley on the bar or other well known means. A frame 13. is secured to the bottom of the elevator and a rop'erlrum 1 1 is rotatably secured at each end in the frame 13. Each rope drum 14: has a pinion 15 on each end firmly secured to or forming a part of the drum. Two wire locking ropes 16. 16. extend the entire height of the elevator well 7, and each wire rope 16. is firmly secured at its top end in the elevator well, then carried one or more times around :a rope drum in the frame 13, and firmly secured at its bot-tom end in the well, as shown in Figs. 1 and 3. Two locking slides 17. 17. are reciprocally secured in the frame 13. Each slide 13. is

constructed to have a bifurcated end 18 formed into two racks 19. 19. adapted to en.- gage with the pinions 15-. 15. 'onthe drums 14. let. The racks 19. 19. curve upward at their inner end and conform withthe pinions 15. 15. and when in engagement with the pinions lock the pinions to the racks. Each slide 17. has an intermediate portion 20 in a position to engage with the locking rope 16. on the drum 14. A coiled spring 21. is interposed between the inner end of each slide 17. and a fixed portion of the frame 13., the tension ofthe spring acting to throw the slides outward when released. A small wire rope 22 is secured to the right hand end of the bar 11. then carried down through the elevator around a pulley 23 and secured to the left hand slide 17. and a similar wire rope 22. is secured to the left hand end of the bar 11 then carried'down through the elevator and around a pulley 23 and secured to the right hand slide 17 as shown in Fig. 2. The pull of the hoisting cable 9 through the bar 11 on the ropes 22. 22. holds the [slides 17. in their normal inward position against the tension of the coiled springs 21. 21. Stops 24. 24. are firmly fixed'in the elevator well at each floor, as shown in Fig. 1. The releasing device consists of a shaft 25 extending through and rotatably secured in the frame 13, a chain 26. secured to and wrapped one or more times around the shaft 25. and then secured at its other end to the right hand slide 17., a similar chain 26. se cured to and wrapped one or more times around the shaft 25 and then secured at its other end to the left hand slide 17., a sprocket wheel 27 secured to the outer end of the shaft 25, a shaft rotatably secured in the side of the elevator 8 in a convenient position for the operator and having a crank 28 on its inner end and a sprocket wheel 29 on its outer end operatively connected by a sprocket chain 30 to the sprocket wheel 27. The crank 28 has a folding handle 31 which is folded back into the crank arm when not in use.

In the normal running conditions the elevator is supported by the bar 11. which is secured to the hoisting cable 9. and the rope drums 14.. 1%. are free to revolve. On the breaking of the hoisting cable 9 the bar 11 drops by gravity assisted by the coiled springs 21. 21. The slides 17. 17. are in stantly forced outward by the coiled springs 21. 21., the racks 19. 19. engage with the pinions 15. 15. on the drums 14. 14. and lock the drums and the portion 20 of the slides 17. 17. engages with the locking rope and prevents slipping of the rope on the drum. The pull of the locking rope 16 on the drum 14 also holds the drum and slide in the locked position. By varying the number of turns of the locking cables 16. 16. around the locking drums 14;. 14. the elevator may be practically stopped. on the instant or brought to a gradual stop. If the elevator should stop between floors, the crank 28 may be operated to release by drawing the slides 17. 17. inward, thus allowing the elevator to drop down to the next floor, when the bifurcated ends 18. 18. of the slides will engage with the stops 24:. 24c. in the elevator well and hold the elevator at the floor line.

Having thus described my invention I claim as new 1. In a safety elevator mechanism, a hoisting cable, a rope drum rotatably secured to the elevator, a wire rope fixed at its upper end in the elevator well then carried one or more times around the rope drum on the elevator and then fixed at its lower end in the elevator well, a slide on the elevator, means on the slide adapted to engage with means on the rope drum to lock the rope drum against rotation, means operatively connecting the slide with the elevator hoisting cable adapted to hold the slide in its normal inoperativeposition and means for automatically locking the slide with the rope drum on the breaking of the hoisting cable.

2. In a safety elevator mechanism, a hoisting cable, a rope drum rotatably secured to the elevator, a wire rope fixed at its upper end in the elevator well then carried a plurality of times around the rope drum on the elevator and then fixed at its lower end in the elevator well, a slide on the elevator, a pinion on the rope drum, a rack on the slide adapted to engage with the pinion on the rope drum, a stop on the slide, means operat-ively connecting the slide with the elevator hoisting cable, adapted to hold the slide in its normal inoperative position and means for automatically moving the slide into engagement with the rope drum on the breaking of the hoisting cable.

8. In a safety elevator mechanism, ahoisting cable, a rope drum rotatably secured to the elevator, a wire rope fixed at its upper end in the elevator well then wrapped a plurality of times around. the rope drum on the elevator and then fixed at its lower end in the well, pinions on the rope drum, a slide on the elevator, said slide having a bifurcated end, racks on the bifurcated end, and a stop, a coiled spring intermediate the slide and a fixed member, and means operatively connecting the slide with the elevator hoisting cable adapted to hold the slide in its normal inoperative position against the tension of the coiled spring.

4. In a safety elevator mechanism, a hoisting cable, a rope drum rotatably secured to the elevator, a wire rope in the elevator well, said rope being fixed at its upper and lower ends and wrapped a plurality of times around the rope drum on the elevator, pinions on the rope drum, a slide on the elevator, said slide having a bifurcated end, racks on the bifurcated end, said racks curving upward at their inner ends and an intermediate member adapted to engage with the rope on the drum, a coiled spring intermediate the slide and a fixed member, means operatively connecting the slide with the elevator hoisting cable adapted to hold the slide in its normal inoperative position against the tension of the coiled spring and means for moving the slide inward by hand against the tension of the coiled spring.

5. In a safety elevator mechanism, a horizontal bar reciprocally secured to the top of an elevator, said bar having the elevator hoisting cable secured thereto, a frame secured to the bottom of the elevator, a rope drum rotatably secured in the frame at each end of the frame, two wire ropes in the elevator well each rope being fixed at its upper and lower end and wrapped a plurality of times around a rope drum on the elevator, pinions on each rope drum, two slides in the frame each slide having a bifurcated end, racks on the bifurcated ends said racks curving upward at their inner ends and forming stops and an intermediate member adapted to frictionally engage with the rope the shaft and operatively connected to the chain shaft and stops fixed in the elevator well at each floor.

In testimony whereof, I have signed my 15 name to this specification in the presence of two subscribing witnesses.

JOHN M. ANDREWS.

on the drum, a coiled spring intermediate each slide and a fixed member on the frame, wire ropes extending downward from the horizontal bar then around pulleys and connected to the slides, a horizontal chain shaft, chains secured to and wrapped around the shaft and then secured to the slides, a sprocket wheel on the outer end of the shaft, a shaft rotatably supported in the side of the elevator, a crank on the inner end of the shaft, a sprocket wheel on the outer end of WVitnesses:

SOLOMON ROSENBERG, CELIA F. ANDREWS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

